To identify the problem, let’s start with the door itself. You can see in the picture below the door sweep at the bottom.

Next, here is the door opened to the cold cellar. Notice the weather stripping on the side and on top of the door frame. They are pretty cheap, easy to install and can be picked up at any hardware store.

However, what is inside the door frame that the weather stripping is on? In our case, nothing but air.

It had never occurred to me to actually look to see that there was some type of insulation there. During the previously mentioned blower test I could feel the cold air from the outside coming into the basement from both sides and the top of the door frame.

Above is a picture of the one side of the door frame where I am trying to show you the air space both within the door frame itself as well as between the door frame and the concrete foundation wall on the right.

And this last picture above is of the door frame. Again, I’m trying to visually show you the space between the top of the cold cellar door frame and the foundational horizontal support beam.

However, in both cases it is not a lot of space. I could, I suppose try to push pink fibreglass insulation into the space. However, they don’t sell single fibreglass bats; you have to buy lots of them at a time. And, it is a pretty narrow area.

To see the solution I used for this area, simply select this link to Part 2.

Comments

In fact, at least Home Depot sells smaller pieces of fiberglass. I don’t remember if it’s a single batt or even less, but I used once a small package. However, fiberglass is not good at all to stop air infiltration. Instead, you should use low-expansion foam (specially formulated for doors and windows)or backing rod + caulking.

You could use only caulk to seal the gap, but if the crack is over 1/4″ the caulk will not stay in place enough to cure.

Now I’ve searched and the proper name is “backer rod”. Search Google Images to see pictures. It is a round foam bar, usually 1/2″ to 1″ in diameter (although you can find even larger sizes) and in different lengths. I bought it in 10 ft packages. You just push it into the gap, to fill it (get the right size, a little bigger than the gap), and then cover tho whole thing with caulk. The caulk will stick to the rod’s surface and to the side wall/door/etc and will create the air barrier. The rods are available at all home improvement stores, search in the weatherstripping department.